“Technology is on the cusp of transforming how people experience AV communications”

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Jérôme Vieron (L) &#38; Benoit Fouchard: “As we progress further, the industry will realise the full magnitude of the production challenge” says Vieron

actual bit rates to the proportion of content that you want delivered without impairment. “We won’t know the ‘real’ savings of

HEVC until subjective evaluations are made with a full hardware decoder and test material with a representative range of criticalities,” he says. “More than that, over time manufactured equipment performance improves within the same system spec so figures become just a snapshot in time.” The percentage gains compared to

AVC for compressing video to mobiles will be greater in practice than those for UHDTV, “because we are not so nit- picky about impairments with video for mobiles,” observes Wood. “In that case we are working with average quality and in the UHDTV case we are less tolerant to any impairment at all because perfect quality is the name of the game.” The draft parameters for a UHDTV

signal format accommodates 8 Mpixel images at 4K and roughly 32 Mpixel images for an 8K system. The quality steps (HD-4K, 4K-8K) are of about the same order as the quality step from SD to HD. “However the colour gamut for both UHDTV systems is larger than for HDTV, and there are two options for creating YUV signals from RGB signals,” explains Wood. “One is the way we use today for HDTV, called ‘non constant luminance coding’, and the other, which will have benefits in some circumstances such as compression, is ‘constant luminance coding’. We’ve done every which way we can to move the quality forward.” The initial version of the HEVC

standard, scheduled to be completed in January 2013, includes a 16x9 aspect ratio, progressive only and for frame rates up to 120Hz. It will be 8 bits/sample, 4:2:0, single layer only with an extension planned for January 2014 which will include 10 bits/sample, 4:2:2 and 4:4:4. The support for a higher frame rate option may be necessary for accurate portrayal of motion at extreme resolutions on large wall sized displays. Pay-TV operators and vendors are

already thinking along such lines. PayTV systems innovator NDS, for example, demonstrated how HD to 4K video on a giant living room screen could be expanded and contracted in accord with content and usage over its proof of concept Surfaces platform at IBC2011.

First applications If a plug-in can be developed for download then the first applications of HEVC can be used almost immediately for carrying HD video over the internet. Encoding specialist Ateme believes there could be early trials and commercial deployment in 4K using MPEG-4 compression using its EAVC4 encoder (see TVBEurope’s July 2012 issue) that it claims delivers 20% efficiencies over existing MPEG-4 technologies. There is already some 4K content

available on-demand and supported by YouTube at a resolution of 4096 x 3072 pixels (12.6 Mpixel). The introduction of 4K-ready TV sets from 2013 will see 4K begin to seep into the home. “It will be interesting to see if tablets

have the processing capacity to decode HD HEVC at conventional picture rates,” says Wood. “Maybe not the versions in the shops today, but soon. HEVC is several times as sophisticated as AVC so it will need more processing capacity, but not by an impossible amount.” With only a few countries to date

using DVB-T2 it is likely that those countries yet to deploy a DVB-T2 system might use a HEVC DVB-T2 scheme. France is one such country already with HEVC on its radar for a DTT 2.0 launch in 2015/16. “Provided there is enough volume

there to make the set top box affordable then HEVC would surely allow more HDTV broadcasting,” notes Wood. “HDTV bit rates will probably be down to 4-5Mbps with HEVC (incidentally similar bit rates at which SDTV began).” Using HEVC for satellite broadcasting outside of NHK’s system, which has a 2020 target for domestic TX, will be limited to cases where it is practical to ask viewers to change their set top boxes or receivers.